David Shaw (diver)

David "Dave" John Shaw (1954 – 8 January 2005) was an Australian scuba diver, technical diver, and airline pilot for Cathay Pacific, who flew the A330-300, A340-300, and A340-600.^[1] He is one of only 11 people who have dived below a depth of 240 metres (800 ft) on self-contained underwater breathing apparatus.^[2]

Dive equipment

Shaw's first rebreather was an Inspiration closed circuit rebreather, which he eventually dived to depths beyond the unit's supposed capability. That prompted him to purchase a Mk15.5, which he modified by removing the analogue electronics and replacing them with the Juergensen Marine Hammerhead digital electronics, in a specially modified POD designed to handle extreme pressures. The Mk15.5 was his rebreather of choice for dives deeper than 150 metres (500 ft). Shaw also owned a Cis-Lunar Mk5P that he used on extended dives in caves shallower than 150 m. He believed the Cis-Lunar had greater redundancy capabilities for such dives but could not cope with extreme depths.

Diving records

On 28 October 2004, Shaw broke the following records at Bushman's Hole, South Africa:

• Depth on a rebreather
• Depth in a cave on a rebreather
• Depth at altitude on a rebreather
• Depth running a line

He used a Mk15.5 with Juergensen Marine Hammerhead electronics and the following gas mixtures: trimix 4/80, 10/70, 15/55, 17/40, 26/25, air, nitrox50, 100% oxygen. The cave elevation was 1,550 metres (5,090 ft) and the dive duration was 9 hours 40 minutes.^[3]

On this record-breaking dive, Shaw discovered the body of Deon Dreyer, a South African diver who had died in Bushman's Hole ten years previously. The body was at a depth of 270 metres (890 ft).^[4][5]

Last dive

Shaw died on 8 January 2005 while seeking to recover the body of Dreyer.^[4][5]

Shaw recorded his dive with an underwater camera, and this recording relayed valuable information that allowed researchers to determine that he suffered from an effort-independent expiratory flow which resulted in an inability to match ventilation to the demands of physical work at that great depth.^[6][7] Shaw ran into difficulties when he cut loose Dreyer's harness and the body unexpectedly began to float. (Shaw had been advised by various experts that the body would remain negatively buoyant because the visible parts were reduced to the skeleton. However, within his wetsuit, Dreyer's corpse had turned into a soap-like substance called adipocere, which floats). Shaw had been working with both hands, and so had been resting his can light on the cave floor. The powerful underwater lights that cave divers use are connected by wires to heavy battery canisters, normally worn on the cave diver's waist, or sometimes attached to their tanks. Normally he would have wrapped the wire behind his neck, but he was unable to do so; the lines from the body bag appear to have become entangled with the light head, and the physical effort of trying to free himself led to his death. The next day, both of the bodies floated up to near the surface as the dive team was retrieving their equipment.

The dive on which Shaw died was the 333rd of his career. At the time of his world record setting dive, he had been diving for just over five years.^[8][9][10]

Personal life

Shaw was a devout Christian. He and his wife, Ann, lived in Hong Kong, where they were members of a small Christian congregation.^[11] They have two children, Steven and Lisa.^[12]

References